Data Management Method and Apparatus

1. A data management method for converting an item in a first hierarchical folder structure into an item in a second hierarchical folder structure, the first hierarchical folder structure being such that a single item that is either data or a folder is registered in either a single or plural folders, the second hierarchical folder structure being such that a single item is registered in a single folder, the method comprising: a relational data acquiring step of acquiring, in the first hierarchical folder structure, a plurality of relational data pieces for items, each relational data piece indicating one item as a child item and indicating one parent folder in which said child item has been registered; an attribute appending step of appending attribute information to each of the acquired relational data pieces, wherein the attribute information includes an access history, and wherein, when an item has been accessed as a child item of a parent folder, an access history included in attribute information appended to a relational data piece indicating said child item and said parent folder is updated; a selection step of, when one of the items is included in plural ones of the relational data pieces, selecting one of the plural ones of the relational data pieces based on the access history; and a conversion step of converting the item included in the selected relational data piece into an item in the second hierarchical folder structure so that the converted item is registered in a single parent folder included in the selected relational data piece, wherein a folder having no child item, which is generated as a result of the conversion, remains in the second hierarchical folder structure as a vacant folder belonging to one of folders to which the vacant folder belonged in the first hierarchical folder structure.

2. The method according to claim 1 , wherein the access history includes an access frequency, and in the selection step, a relational data piece that has been appended with the attribute information including the access history that has a highest value for the access frequency is selected.

3. The method according to claim 1 , wherein the access history includes an access date and time, and in the selection step, a relational data piece that has been appended with the attribute information including the access history that has a latest value for the access date and time is selected.

4. The method according to claim 1 , further comprising: a setting step of, when one of the items is included in a plurality of relational data pieces acquired in the relational data acquiring step, causing a user to set up master-slave information in which one of the plurality of relational data pieces is registered as a master and any relational data piece other than the master is registered as a slave, wherein in the attribute appending step, attribute information including the master-slave information is appended to a relational data piece that has been registered as the master according to the master-slave information, and in the selection step, a relational data piece that has been appended with the attribute information including the master-slave information according to which the relational data piece has been registered as the master is selected.

5. The method according to claim 1 , wherein, the parent folders are appended with information that indicates access rights to the parent folders, and in the selection step, one of the plurality of relational data pieces that includes a parent folder that permits a specific user to have access rights is selected.

6. The method according to claim 1 , further comprising a registration step of, in the conversion step, registering either a shortcut or a link to the converted item in a folder obtained by converting a parent folder that is included in an unselected one of the relational data pieces that include a pre-conversion item from which the converted item has been obtained.

7. A computer-readable recording medium storing a computer program that causes a computer to perform the data management method according to claim 1 .

8. The method according to claim 1 , wherein the attribute information includes a user identifier, and wherein, in the selection step, a relational data piece is selected based on a current user and a user identifier in the attribute information.

9. The method according to claim 1 , wherein the item included in the selected relational data piece is included in the first hierarchical folder structure in which a single item can be registered in multiple parent folders, and wherein the converted item is in the second hierarchical folder structure in which a single item can be registered in only a single parent folder.

10. A data management apparatus for converting an item in a first hierarchical folder structure into an item in a second hierarchical folder structure, the first hierarchical folder structure being such that a single item that is either data or a folder is registered in either a single or a plurality of folders, the second hierarchical folder structure being such that a single item is registered in a single folder, the apparatus comprising: a relational data acquiring unit configured to acquire, in the first hierarchical folder structure, a plurality of relational data pieces for items, each relational data piece indicating one item as a child item and indicating one parent folder in which said child item has been registered; an attribute appending unit configured to append attribute information to each of the acquired relational data pieces, wherein the attribute information includes an access history, and wherein, when an item has been accessed as a child item of a parent folder, an access history included in attribute information appended to a relational data piece indicating said child item and said parent folder is updated; a selection unit configured to select one of plural ones of the relational data pieces based on the access history when one of the items is included in the plurality of relational data pieces; and a conversion unit configured to convert the item that is included in the selected relational data piece into an item in the second hierarchical folder structure so that the converted item is registered in a single parent folder that is included in the selected relational data piece, wherein a folder having no child item, which is generated as a result of the conversion, remains in the second hierarchical folder structure as a vacant folder belonging to one of folders to which the vacant folder belonged in the first hierarchical folder structure, and wherein at least one of the relational data acquiring unit, the attribute appending unit, the selection unit, and the conversion unit includes at least one of a memory and a processor.

11. The data management apparatus according to claim 10 , wherein the item included in the selected relational data piece is included in the first hierarchical folder structure in which a single item can be registered in multiple parent folders, and wherein the converted item is in the second hierarchical folder structure in which a single item can be registered in only a single parent folder.